Colorado lawmakers have introduced legislation that seeks to protect patients from high, unexpected medical bills, according to KDVR, a Fox-affiliated TV station.

Five things to know:

1. Patients often face surprise medical bills when they're referred by in-network providers to providers who are not in their insurance company's network.

2. Colorado lawmakers hope to limit the amount patients could be charged in these situations, according to KDVR.

3. Proposed legislation would apply to state-regulated insurance plans but not when patients seek out-of-network care.

4. Under the bill, charges would reportedly be limited to 125 percent the Medicare payment rate, the average in-network rate for the geographical area, or the average in-network rate based on the "All Payer Claims Database."

5. The Colorado Hospital Association has expressed concerns about the proposed bill.

Katherine Mulready, senior vice president and chief strategy officer of the association, told KDVR: We are concerned that the bill as introduced falls short. Setting a 'default' payment rate for hospitals that are not in an insurer's provider network will have ripple effects in the market if the default rate is too low. In particular, hospitals may not be able to negotiate as effectively with insurance carriers to ensure fair payments for all of the essential services they provide."